Polycarboxylic acid salts of alkylene nitrogen compounds as fuel detergents

ABSTRACT

ALIPHATIC POLYCARBOXYLIC ACID SALTS OF AMINE NITROGEN CONTAINING COMPOUNDS FIND USE AS FUEL DETERGENTS HAVING IMPROVED WATER TOLERANCE.

Feb. 23, 1971 MEHMEDBASlCH 3,565,592

POLYCARBOXYLIC ACID SALTS OF ALKYLENE NITROGEN COMPOUNDS AS FUELDETERGENTS Filed NOV. 14, 1968 A COMPARISON OF THE WATER TOLERANCE OFPOLYISOBUTENYL TETRAETHYLENE PENTAMINE AND ITS CARBOXYLIC ACID SALTSA-UNNEUTRALIZED AMINE HAZE RATING B- 90%NEUTRALIZED WITH OXALIC ACIDIOO%NEUTRALIZED WITH-C TARTARIC ACID 1 I l l l I o 2 4 s a 10 TIMEMINUTES 30 FIG. I

E A COMPARISON OF THE WATER TOLERANCE OF POLYISOBUTENYL TETRAETHYLENE 9PENTAMINE AND ITS CARBOXYLIC ACID SALTS m I .J D E 10 O I I I I l TIME,MINUTES Fl G. 2

INVENTOR ENVER MEHM BASICH BY Kb [Is R:

ATTORNEYS United States Patent 3,565,592 POLYCARBOXYLIC ACID SALTS OFALKYL- ENE NITROGEN COMPOUNDS AS FUEL DETERGENTS Enver Mehmedbasich,2061 Key Blvd., El Cerrito, Calif. 94530 Filed Nov. 14, 1968, Ser. No.775,716

Int. Cl. Cl 1/22 US. CI. 4463 13 Claims ABSTRACT OF THE DISCLOSUREAliphatic polycarboxylic acid salts of amine nitrogen containingcompounds find use as fuel detergents having improved water tolerance.

BACKGROUND OF THE INVENTION Field of the invention Deposits resultingfrom polymeric materials in fuels remain a continuing problem in thesmooth operation of internal combustion engines. Recently, a number ofbasic amine nitrogen containing fuel detergent additives have beenincorporated into fuels to reduce deposit formation. These additiveshelp by maintaining various parts of the engine in clean condition, andby reducing incomplete combustion. Thus the additives contribute tolonger engine life, improved fuel performance and reduction of theproduction of smog-producing exhaust problems.

These additives, for the most part, have one or more long chainaliphatic hydrocarbon groups bonded to a polyamine either directly orthrough a nonoxo carbonyl group forming amides, amic acids, imidazolinesor imides.

Because these detergents are frequently excellent emulsifiers, it isfound that when the fuels containing the detergents are shaken withwater, the separation of the fuel from the water and the clarity of thefuel phase are not as good as desired. That is, a relatively large cuffforms which is quite stable and significant water is retained in thefuel phase so as to cause a haze. This phenomenon referred to as watertolerance varies, depending on the particular composition of the fueldetergent.

The problem of water tolerance can be acute with fuels which come incontact with water. In many storage tanks, the housekeeping is fairlypoor and water collects at the bottom of the tank. When fuel isintroduced into the tank or withdrawn, significant agitation may occur.If the fuel and water do not separate quickly, significant amounts ofWater may be Withdrawn with the fuel. Or, a cuff results, which meansloss of fuel. If water is retained in the fuel phase, the fuel appearshazy and is unacceptable.

Also transferring by means of a centrifugal pump can result inhomogenization of water and fuel, if a water phase is present in theholding tank. Rapid separation of the water from the fuel is essential,if the fuel is to be in condition for use.

Description of the prior art US. Pats. Nos. 2,945,749, 3,050,043, and3,231,348 disclose relatively low molecular weight amine derivatives asfuel detergents.

U.S. Pats. Nos. 2,905,542, 3,007,782, 3,118,745 and 3,228,758 discloseamine salts as deicing agents and anticorrosion agents in fuels.

U.S. Pats. Nos. 3,219,666 and 3,275,554 disclose basic amine nitrogencontaining lubricating oil detergents, which have since been reported tobe useful in fuels.

ICC

SUMMARY OF THE INVENTION Aliphatic polycarboxylic acid salts of aminenitrogen containing fuel detergents, having at least one aliphatichydrocarbon chain of at least 30 carbon atoms, are provided as fueldetergents having greatly improved water tolerance. The polycarboxylicacids are of from 2 to 8 carbon atoms and are free of substituents otherthan hydroxyl.

Brief description of the drawing FIG. 1 is a graph of haze rating versustime for Water tolerance determinations according to a modified versionof ASTM D l09457 having polyisobutenyl tetraethylene pentamineneutralized with oxalic acid and tartaric acid.

FIG. 2 is a graph of the emulsion volume versus time for the samecompositions employed for FIG. 1 and under the same test conditions.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The compositions of thisinvention will, for the most part, fall into one of three categories.The compositions of this invention Will be organic polycarboxylic acidsalts of (1) aliphatic hydrocarbon substituted alkylene polyamines; (2)alkyl or alkenyl succinimides of alkylene polyamines; and (3) aliphaticcarboxamides or imidazolines of alkylene polyamines.

Aliphatic hydrocarbon substituted alkylene polyamines The compositionsWithin the first group will, for the most part, have the followingformula:

(x/n) Y.{ (I\|I( (U-I I) (U-N N) p R H wherein U is alkylene of from 2to 6 carbon atoms, more usually of from 2 to 3 carbon atoms, there beingat least 2 carbon atoms between the nitrogen atoms. R is substantiallyaliphatic hydrocarbon radical of from about 420 to 5,000 averagemolecular Weight, more usually of from from 450 to 3000 molecularweight, usually having at least one branch of from 1 to 6 carbon atomsper six carbon atoms along the chain. a is an integer of from 0 to 5; bis an integer of from 0 to 1; a+2b is an integer of from 1 to 5. c is aninteger of from 1 to 3 and is on the average in the range of about 1 to2. x is in the range of from .75 to 1 times the titratable aminenitrogen. n is the number of carboxylic acid groups of the carboxylicacid Y. And, Y is an aliphatic polycarboxylic acid of from 2 to 3carboxyl groups and of from 2 to 8 carbon atoms, which is free ofsubstituents other than hydroxyl, and the unsubstituted polybasic acidsare incapable of forming unimolecular cyclic anhydrides of from 5 to 6annular members.

Preferred aliphatic hydrocarbon substituted alkylene polyamines willhave the following formula:

wherein R is an oil soluble branched chain aliphatic hydrocarobn radicalof from about 450 to 5,000 average molecular weight, more usually 450 to3,000 molecular weight, usually having at least one branch of from 1 to2 carbon atoms per 4 carbon atoms along the chain, and preferablypolypropylene or polyisobutylene; U is alkylene of from 2 to 3 carbonatoms, there being at least 2 carbon atoms between the nitrogen atoms; Yis as defined previously; a is an integer of from 1 to 4; c is aninteger of from 1 to 3; x is at least 0.75 times and usually in therange from 0.8 to 1 times the number of titratable amine nitrogen atomsand n is the number of carboxylic acid groups of the organic acid Y.

The alkylene polyamines which find use in preparing the organic acidsalts of this invention have the following formula:

I I l -N)( -N N )bl) c 3+n-u wherein all the symbols have been definedpreviously when defining the salt.

Succinimides The next group of compositions are the reaction products ofalkyl or alkenyl succinic anhydrides and alkylene polyamines. Theproducts are prepared by reacting the anhydride and the amine underdehydrating conditions, wherein imides are formed, as well as some amicacid and diamide. Also, depending on the ratio of reactants, one or moreof the anhydrides may react to form the various possible products. Ifmore than 2 anhydrides are used per mole of alkylene polyamine, clearly,the third anhydride cannot form an imide. Therefore, the compositionsare best described by treating them as a product by process. (See U.S.Pat. No. 3,219,666.)

The compositions are prepared by reacting under dehydrating conditions(85 250 C.) an aliphatic hydrocarbon substituted succinic anhydride ofthe following formula:

CI'IQ-CO wherein R is alkyl or alkenyl of from 30 to 200* carbon atomshaving at least one branch of from 1 to 2 carbon atoms per 4 carbonatoms along the chain, and preferably polypropylene or polyisobutylene,with an alkylene polyamine of the following formula:

( t( I-).( N-(rbfiu.

wherein the symbols have been defined previously. The mole ratio ofanhydride to alkylene polyamine will generally be from 1 to 3, moreusually of from 1 to 2.

With only 2 moles of anhydride, and more likely with only 1 mole ofanhydride per mole of alkylene polyamine the major product will besuccinimides. Therefore, as a good approximation the compositions may bedescribed by the formula of the succinimide as follows:

X(-UNH-) UX where at least 1 of the Xs is:

R -0H o o R bleing defined previously, the other X being the same oramino; U is alkylene of from 2 to 6 carbon atoms, more usually of from 2to 3 carbon atoms, there being at least 2 carbon atoms between thenitrogen atoms; 1 is 1 to 5.

The anhydride-alkylene polyamine reaction product will have at least .75times, and usually 0.8 to 1 times the amount of titratable aminenitrogen neutralized with the organic polycarboxylic acids previouslydescribed. Therefore, the formula as the salt would have (x/n)Y includedtherein, the symbols being previously described.

Carboxamides of alkylene polyamines The third category of compositionsare the carboxamides which, for the most part, are included in thefollowing formula:

-fi at (x/n)Y N{ \U N a \U N N b (R CO )c ii-ta I: wherein X, N, a, b,c, U and Y have all been defined previously, and R is an aliphatichydrocarbon group of from 30 to 200 carbon atoms, either alkyl oralkenyl, usually having at least 1 branch of from 1 to 2 carbon atomsper Reactants The alkylene polyamines, which when combined with a longchain hydrocarbon group find use in this invention, are those of from 3to 6 amine nitrogen atoms and of from 6 to 30 carbon atoms, more usuallyof from 6 to carbon atoms.

Illustrative alkylene polyamines which may be substituted with ahydrocarbon radical, either directly or through an acyl (nonoxocarbonyl) group, are illustrated by diethylene triamine, tetraethylenepentamine, Z-aminoethyl piperazine, dipropylene triamine,ditetramethylene triamine, dihexamethylene triamine, tris-aminoethylamine, etc.

In many instances, a single compound is not used as a reactant in thepreparation of the hydrocarbon substituted amine. That is, mixtures willbe used, wherein one or 2 compounds will predominate and the averagecomposition or molecular weight is indicated. For example, tetraethylenepentamine prepared by the polymerization of aziridine or reaction ofdichloroethylene and ammonia will have both lower and higher member, e.g., triethylene tetramine and pentaethylene hexamine. But, thecomposition will be mainly tetraethylene pentamine and the empiricalformula of the total composition will closely approximate that oftetraethylene pentamine.

Similarly, the molecular weight reported for the long chain aliphatichydrocarbon group is an average for a mixture which is sharply peakedwhen graphing the number average molecular weight distribution. That is,at least weight percent of the composition will be within 20 weightpercent of the average molecular weight reported.

Also, as the formulas suggest, the particular position of thesubstituting group is frequently not known and may be on any of thenitrogens. Therefore, when preparing the compositions, mixtures areinherently prepared.

The long chain hydrocarbon group bonded to the amine nitrogen, eitherdirectly or through an acyl group, is preferably a branched aliphatichydrocarbon, substantially free of aromatic unsaturation, having 0 to 1site of olefinic unsaturation. These compositions are readily preparedby the polymerization of low molecular weight olefins, although othersources may be found and used. The group should be fuel solubilizing andtherefore preferably branched, having about 1 branch per 6 carbon atomsalong the chain, preferably per 4 carbon atoms, usually of from 1 to 2carbon atoms and more usually methyl. Illustrative hydrocarbon chainsare polypropylene, polyisobutylene, copolymers of ethylene and propyleneor ethylene and isobutylene, etc.

As already indicated, the organic acids are polycarboxylic acids havingfrom 2 to 3 carboxylic acid groups and of from 2 to 8 carbon atoms. Theyare free of substitution other than hydroxyl. There may be from 1 to 3hydroxyl groups. Usually, there will be not more than 1 site ofaliphatic unsaturation, e.'g., ethylenic or acetylenic. Theunsubstituted polycarboxylic acids are restricted to those which cannoton heating form a cyclic anhydride of from 5 to 6 annular members.

Illustrative polycarboxylic acids include malic acid, citric acid,fumaric acid, trans-pentene-dioic acid, oxalic acid, malonic acid,tartaric acid, acetylene dicarboxylic acid, etc.

The salts employed in this invention are readily prepared by combiningin a suitable medium the carboxylic acid and hydrocarbon substitutedamine in the appropriate proportions. (The method for determining thetitre of the amine will be described subsequently.) Useful mediumsinclude alcohols, mixtures of alcohols and hydrocarbons, e.g.,tert.-butyl alcohol and toluene. These volatile materials may then beremoved and the product isolated, if desired. By suitable choice ofsolvent, the product may be obtained directly as a concentrate for usein combining with fuels.

The preparation of the substituted amines has appeared in copendingapplication Ser. No. 647,611, filed June 21, 1-967, and now US.3,438,757.

The detergent will generally be employed in a hydrocarbon base liquidfuel. The detergent additive may be formulated as a concentrate, using asuitable hydrocarbon alcohol solvent boiling in the range of about 150to 400 F. Preferably, an aromatic hydrocarbon solvent is used, such asbenzene, toluene, xylene or higher boiling aromatics or aromaticthinners. Aliphatic alcohols of about 3 to 8 carbon atoms, such asisopropanol, isobutylcarbinol, n-butanol and the like, in combinationwith hydrocarbon solvents are also suitable for use with the detergentadditive. In the concentrate, the amount of the additive will beordinarily at least 10 percent by weight and generally not exceed 70percent by weight.

The amount of the detergent used in the fuel will generally be at least50 and more usually from about 100 to 1,000 ppm.

in gasoline fuels, other fuel additives may also be included such asantiknock agents, e.g., tetramethyl lead or tetraethyl lead. Alsoincluded may be lead scavengers such as aryl halides, e.g.,dichlorobenzene or alkyl halides, e.g., ethylene dibromide.

A nonvolatile lubricating mineral oil, e.g., petroleum spray oil,particularly a refined naphthenic lubricating oil having a viscosity at100 F. of 1,000 to 2,000 SUS, is a suitable additive for the gasolinecompositions having the detergents of this invention and its use ispreferred. These oils are believed to act as a carrier for the detergentand assist in moving and preventing deposits. They are employed inamounts from about 0.05 to 0.5 percent by volume, based on the finalgasoline composition.

EXAMPLES The illustrative preparation of the tartrate salt ofpolyisobutenyl tetraethylene pentamine will suifice to exemplify themethod of preparation for all the salts prepared.

ExampleI A 50 weight percent solution in a C aromatic solvent ofpolyisobutenyl tetraethylene pentamine (polyisobutenyl of about 1,000molecular weight) was titrated as follows. Approximately 0.5 g. of theabove solution was dissolved in a solution having 20 volumes of benzene,75 volumes of isopropyl alcohol and volumes of distilled water. Thesolution was potentiometrically titrated with approximately 0.1 NormalHCl, graphing the course of the titration. The mid-point of the curve(pH of about 5.3) determines the amount of titratable nitrogen. By thistitration, the equivalent of the solution was found to be 682. Tartaricacid was obtained as 99.9 weight percent pure and was presumed to have 2equivalents per mole.

The tartaric acid (75 g.) was dissolved in tert.-butyl alcohol in abeaker on a hot plate. To the beaker was added with stirring, 682 g. ofthe solution described above. Stirring was continued until the solutionappeared homogeneous. The solution was then transferred to a distillingflask and the tert.-butyl alcohol distilled off. Toluene was then addedto the residue to obtain a final weight of 832 g.

Salts of numerous other polybasic carboxylic acids were preparedsimilarly. In order to demonstrate the excellent water tolerance of thevarious salt mixtures emp oyed in this invention, the test procedure ofmodified ASTM D1049-57 was employed. The following table indicates theresults obtained after 10 minutes, using distilled water. The resultsare reported for those salts which demonstrated significant improvementin water tolerance over the base fuel containing polyisobutenyltetraethylene pentamine, as well as for some which did not. Significantimprovement is evidenced by the increasing rate at which the water andfuel layer separate and the haze of the fuel layer drops. (The fuel usedis a commercially-available gasoline free of additives.)

TABLE I Composition Rating 2 Citric acid Tartaric acid Oxalic acid Malicacid Adipic acid 3 Malonic acid i- Fumaric acid Maleic acid Lactic acidTerephthalic acid Succinic acid 1 The salts are 100% neutralizedpolyisobutenyl tetraethylene pentamine. The method of preparation andamine are de scribed in Example I. A concentration of 250 p.p.m. wasused.

2 significant improvement in water tolerance 1 some impnovement in waterltolerance; no improvement in water tolerance.

3 neutralized.

Also tested were the oxalate and tartrate salts of a polyisobutenylsuccinimide of tetraethylene pentamine (polyisobutenyl of about 1,000molecular weight.)

The results are evaluated as follows: The haze rating is a rating basedon a rating of 1 to S; the cylinder is observed agamst a flat verticalplate of diffused white light. Horizontal black strips are fixed to thesurface of the plate. The graduated cylinder is placed in front of theplate and the haze rating determined by the degree of difiuseness of theblack strips. A sharp appearance is rated as 1; an almost totallyobscured strip is rated as 5. Also reported are the milliliters ofemulsion that are present at the end of the 10 minutes.

1 Succinimide is polyisobutenyl succinimide oi tetraethylene pentamine(polyisobutenyl of about 1,000 average molecular weight). Concentrationin fuel 15 250 ppm.

To further demonstrate the excellent water tolerance of the salts ofthis invention, the accompanying figures indicate the significantimprovement of the oxalate and tartrate salts as compared to the basepolyisobutenyl tetraethylene pentamine (polyisobutenyl of about 1000molecular weight, about 1:1 mole ratio of polyisobutenyl totetraethylene pentamine) at concentrations of 250 ppm. While the basefuel containing the base amine at 10 minutes has a haze rating of about3.5, both of the fuels containing salts have a haze rating of less than2. Furthermore, the base amine containing fuel has 24 m1. of emulsion atthe end of 10 minutes as compared to about 3 ml. of emulsion at the endof 10 minutes for either of the fuels containing the salts.

To demonstrate that the compositions of this invention still areeffective as fuel detergents, the following test was carried out. A basefuel having a boiling range of 102 to 414 F.; 58 percent paraifins, 22percent aromatics, and 20 percent olefins (by volume) and a vaporpressure (Reid) of 7.4 was employed. The additive was incorporated at aconcentration of 250 ppm. and included in the fuel is 1,750 ppm. of apetroleum spray oil Zerolene 9).

The test is carried out with a single cylinder CFR engine equipped withthrottle. The operating conditions for the test arezjacket temperature,212' F.; oil temperature, 150180 F.; intake air temperature, 95 F.;ignition timing, 15 BTC; intake manifold vacuum, 15 in. Hg; fuel/airratio, 0.07; speed, 1,800 rpm. The duration of the test is 12 hrs.

The intake valve is weighed at the end of the test, cleaned and tared.The intake port is washed with hexane, then fitted with a receiver, andthe deposits removed mechanically with the aid of chloroform. Thechloroform is evaporated at about 250 F. and the deposits weighed.

The following table indicates the results:

TABLE III Deposits 2 Additive 1 Ports, mg. Valves, mg.

N 38 214 A-90% oxalate 14 2 9 2 A 100% tartrate 1 40 B 90% oxalate 33(2)15(2) B-100% tartrate. 8 17 A-polyisobutenyl tetraethylene pentamine(polyisobutenyl of about 1,000 average molecular weight; about onepolyisobutenyl group per tetraethylene pentarnine); Bpolyisobutenylsuccinimide of tetra ethiylege pentamine (polyisobutenyl of about 1,000average molecular we g 2 The number in parentheses indicates the numberof runs averaged for the reported result.

wherein R is a substantially aliphatic hydrocarbon radical of from about420 to 5,000 average molecu lar Weight;

(2) the reaction product of from 1 to 3 moles of an aliphatichydrocarbon substituted succinic anhydride of the formula:

R2CHCO /0 0132-00 wherein R is alkyl or alkenyl of from to 200 carbonatoms and an alkylene polyamine of the formula:

neutralized to from .75 to 1 times the amount of titratable aminenitrogen with the organic polycarboxylic acid Y; and

(3) a salt of the formula:

wherein R is an aliphatic hydrocarbon group of from 30 to 2.00 carbonatoms and wherein in all the formulas, U is alkylene of from 2 to 6carbon atoms; a is an integer of from 0 to 5; b is an integer of from 0to 1; a-l-Zb is an integer of from 1 to 5; c is an integer of from 1 to3; x is in the range of .75 to 1 times the titratable amine nitrogen; nis the number of carboxylic acids of the carboxylic acid Y and Y is analiphatic polycarboxylic acid of from 2 to 3 carboxyl groups and of from2 to 8 carbon atoms, having from 0 to 3 hydroxyl substituents, and theunsubstituted polycarboxylic acids are incapable of forming unimolecularcyclic anhydrides of from 5 to 6 annular members.

2. A composition according to claim 1 wherein U is alkylene of from 2 to3 carbon atoms and R, R and R are polyisobutene.

3. A composition according to claim 1 wherein Y is oxalic acid.

4. A composition according to claim 1 wherein Y is tartaric acid.

5. A composition according to claim 1 wherein said fuel detergent is ofthe formula:

( I/ 1) Y. l Rl IH L Z wherein R is an oil soluble branched chainaliphatic hydrocarbon radical of from about 450 to 5,000 averagemolecular weight; U is alkylene of from 2 to 3 carbon atoms; Y is analiphatic carboxylic acid of from 2 to 3 carboxyl .groups and of from 2to 3 carbon atoms, having from 0 to 3 hydroxyl groups, and theunsubstituted polybasic acids are incapable of forming unimolecularcyclic anhydrides of from 5 to 6 annular members; a is an integer offrom 1 to 4; c is an integer of 1 to 3; x is in the range from 0.8 to 1times the number of titratable amine nitrogen atoms and n is the numberof carboxyl groups of the organic acid Y.

6. A salt useful as a fuel detergent and having enhanced water tolerancecomprising a member of the group consisting of:

(1) a salt of the formula:

wherein R is a substantially aliphatic hydrocarbon radical of from about420 to 5,000 average molecular weight;

(2) the reaction product of from 1 to 3 moles of an aliphatichydrocarbon substituted succinic anhydride of the formula:

wherein R is alkyl or alkenyl of from 30 to 200 carbon atoms and analkylene polyamine of the formula:

neutralized to from .75 to 1 times the amount of titratable aminenitrogen with the organic polycarboxylic acid Y; and,

(3) a salt of the formula wherein R is an aliphatic hydrocarbon group offrom 30 to 200 carbon atoms, and

wherein in all the formulas, U is alkylene of from 2 to 6 carbon atoms;a is an integer of from to b is an integer of from 0 to 1; a+2b is aninteger of from 1 to 5; c is an integer of from 1 to 3; x is in therange of .75 to 1 times the titratable amine nitrogen; n is the numberof carboxylic acids of the carboxylic acid Y and Y is an aliphaticpolycarboxylic acid of from 2 to 3 carboxyl groups and of from 2 to 8carbon atoms, having from 0 to 3 hydroxyl substituents, and theunsubstituted polybasic acids are incapable of forming unimolecularcyclic anhydrides of from 5 to 6 annular members. 7. A salt according toclaim 6 wherein Y is oxalic or tartaric acid.

8. A salt according to claim 6 wherein U is alkylene of from 2 to 3carbon atoms.

9. A salt according to claim 6 wherein said salt is the formula:

(x/n) Y-{ (N (UI I-) El(U-N N) bl) LR H r r wherein R is polypropyleneor polyisobutylene of from 450 to 3,000 molecular weight; U is alkyleneof from 2 to 3 carbon atoms; a is an integer of from O to 5; b is aninteger of from 0 to 1; a+2b is an integer of from 1 to 5; c is aninteger of from 1 to 3; x is in the range of .75 to 1 times thetitratable amine nitrogen; n is 2 and Y is oxalic or tartaric acid. 10.A salt according to claim 6 wherein said salt is the reaction product offrom 1 to 3 moles of an aliphatic substituted succinic anhydrdide of theformula:

10 wherein R is polypropenyl or polyisobutenyl of from 30 to 200 carbonatoms and an alkylene polyamine of the formula:

wherein U is alkylene of from 2 to 3 carbon atoms; a is an integer offrom 0 to 5; b is aninteger of from 0 to l; a+2b is an integer of from 1to 5, neutralized to from 0.75 to 1 times the amount of titratable aminenitrogen with oxalic or tartaric acid.

11. A fuel concentrate composition having a suitable solvent foradmixture with a liquid hydrocarbon fuel boiling in the range of 150 to400 F. and from 10 to weight percent of a salt according to claim 6.

12. A fuel concentrate composition having a suitable solvent foradmixture with a liquid hydrocarbon fuel boiling in the range of to 400F. and from 10 to 70 weight percent of a salt according to claim 9.

13. A fuel concentrate composition having a suitable solvent foradmixture with a liquid hydrocarbon fuel boiling in the range of 150 to400 F. and from 10 to 70 weight percent of a salt according to claim 10.

References Cited UNITED STATES PATENTS 2,839,373 6/19 58 Barusch et al.4466 3,219,666 11/1965 Norman et al. 25251.5A 3,438,757 4/1969 Honnen etal. 44-63X 3,468,639 9/1969 Lindstrom et al. 44-71X DANIEL E. WYMAN,Primary Examiner W. J. SHINE, Assistant Examiner US. Cl. X.R.

92353 UNITED STA! 12s .m'rm'r OFFICE CERTIFICATE OF CORRECTION PatentNo. 3 ,565 592 Dated E 1223mm! 23 392] Inventor s) ENVER MBHMEDBASI CHIt is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

line 60, "hydrocarobn" should read -hydrocarbon--.

C01. 3 line 47 X(UI\ TH} UX" Should read --X(UNH) UX-;

line so "R cH- co should read --R2-CHCO Col. 5, lines l b-16, delete thesentence starting with "The and ending with '3 ,H38 ,757 Insert in lieuthereo. --In copending application Serial No. 647 ,Sll, file June 21,1967, and now U.S. 3, +38,7S7, the method of preparation is consideredsuperfluous.-

Col. 7, line 70, "((R CO-) H should read I Col. 8, line 28, "XInUY'({-N(U N-) 1 1 1 2 I I L should read ---x /n )Y' {-N(-U N-) 1 R 1 11-- Signed and sealed this 11 th day of September 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK

